The main role of the Independent Police Complaints Commission (IPCC) is to bring the full facts to light when independently investigating a death in police custody. The IPCC has come in for severe criticism on many occasions but never more so than in last week's independent review of its investigation into the death of Sean Rigg at Brixton police station in August 2008.

Led by criminologist Silvia Casale, the report is a damning indictment of the IPCC's failings. Among its findings are that investigators failed to control events at the outset, allowing police officers to confer when writing their initial accounts, and there was a shrugging acceptance of "implausible" police accounts of Rigg's behaviour and "improbable" assertions that he didn't appear mentally ill. It is refreshing and welcome in the light of this damning indictment that the chair of the IPCC, Dame Anne Owers, promises to implement all the review's recommendations. However, it beggars belief that the IPCC has agreed to adopt basic investigative practices only in the 10th year of its existence.

Inquest, the charity that worked with the family of Sean Rigg, has pointed out his is not an isolated case. This is indicative of broader systemic problems that must be addressed, beginning with the implementation of Casale's recommendations.

The Casale report is a watershed for the police service and the IPCC: the former must systematically drag police practice up to an acceptable level when providing adequate care to vulnerable people and eliminating the disproportionate use of force and restraint; while the IPCC must fearlessly hold all concerned properly to account whenever someone dies or is seriously injured in police custody.

Confidence in the police and the police watchdog is already at its nadir. Positive action has to be the only way forward.